These days you can use any brand of servo you choose.

I have Futaba, Hitec, and GWS 72Mhz receivers and Airtronics 2.4Ghz receivers. I use JR, Airtronics, Hitec, GWS, Hextronic, Futaba, and Ace servos with all of these brands of servo in no particular relation.

Protege 60 ARF: Airtronics 92824 receiver and JR ST-47 servos
VMar Ramrod 40: Airtronics 92824 receiver and Hitec HS-311 servos
King Kobra 60: GWS RD8SL receiver and Hitec HS-425BB servos
Staudacher S-300: Futaba R138PM receiver and Futaba S3151 servos on control surfaces and Ace 1903 servo on throttle
Sig E-Force ARF: GWS Pico 4 receiver with Hitec HS-55 and Hextronic HXT900 servos
Phoenix Dolphin 40: Airtronics 92824 receiver and Airtronics 94102Z servos
Thunder Tiger Mini Titan E325 heli: Airtronics RX 60 receiver and Ace C1016 servos
Thunder Tiger Tiger Stick: Airtronics 92824 receiver and Futaba S3003 servos

Servos and receivers are largely all cross-compatible these days with very, very few exceptions.